Make a "config.php" file with these contents:
<?php
$header = "/var/www/html/header.html";
$menu = "/var/www/html/menu.html";
?>
Then edit index.php, page1.php, page2.php and the rest of the pages and add this code at the beginning:
<?php
require_once($header);
require_once($menu);
?>
<html>
blah blah blah your page blah blah blah whatever blah
</html>
Then you just open header.php and menu.php and make whatever kind of banner (header.php) for your site and create the menu (menu.php).
What this does is assign specific pages to a variables. You tell the webserver what variables exist and what static pages those variables refer to (config.php). Each time you type "require_once("/var/www/html/config.php");" the webserver will load those variables into memory so it knows where to look if you call those variables.
Then, in your individual website pages, typing "require_once($header);" will call copy whatever code is in that file that's assigned to the $header variable and paste it into the file, right where you called it.
As an example, let's say you have this for your header.php file:
<html>
<center>
<img src="website_banner_picture.jpg">
</center>
</html>
Let's also say that you have this for your menu.php file:
<html>
<a href="page1.php">Page 1</a>
<a href="page2.php">Page 2</a>
<a href="page3.php">Page 3</a>
</html>
Let's also say that you have this in your index.php file:
<?php
require_once($header);
require_once($menu);
?>
<html>
Hello World
</html>
When someone goes to your domain, they're going to see a page much larger than just those few lines of code in your index file because it's pulling all the code from those $header and $menu files. They'll see this code:
<html>
<center>
<img src="website_banner_picture.jpg">
</center>
</html>
<html>
<a href="page1.php">Page 1</a>
<a href="page2.php">Page 2</a>
<a href="page3.php">Page 3</a>
</html>
<html>
Hello World
</html>
Make sense? With some creativity and tables, you can create quite the complicated website with just a few lines of code instead of hard-coding each individual page. You just have to include that first bit in each file, which you don't even have to change at all later if you want to change the content of the menu or the header or whatever other kinds of pages that you want to have included all in one page. You just edit those header.php, menu.php, footer.php, or whatever and because it's all dynamically called, all of your pages get updated.
Let your creativity take this and run with it. It's a very simple idea once understood and very powerful.